Sleep Recordings and Hypnograms in European Data Format (EDF)

This collection of 61 polysomnograms (PSGs) with accompanying hypnograms
(expert annotations of sleep stages) comes from two studies (briefly described
below, and in detail in [1,2]). A small subset of this
dataset was previously contributed in 2002 and remains available
here for reference and
to support ongoing studies. In the present dataset, all EDF header
fields also comply with the EDF+ specs, and unrecorded signals were
removed from the ST*PSG.edf files.

The *PSG.edf files are whole-night polysmnographic sleep recordings
containing EEG (from Fpz-Cz and Pz-Oz electrode locations), EOG (horizontal),
submental chin EMG, and an event marker; the SC*PSG.edf files often
also contain oro-nasal respiration and rectal body temperature. The
*Hypnogram.edf files contain annotations of the sleep patterns that
correspond to the PSGs. These patterns (hypnograms) consist of sleep stages W,
R, 1, 2, 3, 4, M (Movement time) and ? (not scored). All hypnograms were
manually scored by well-trained technicians (identified by the eighth letter of
the hypnogram filename) according to the 1968 Rechtschaffen and Kales
manual [3], but based on Fpz-Cz/Pz-Oz EEGs instead of
C4-A1/C3-A2 EEGs, as suggested by
[4]).

The PSG files are formatted in EDF while the hypnograms are in EDF+. The
specifications of EDF and EDF+ are on www.edfplus.info and in [5,6]. Each EDF
and EDF+ file has a header specifying the patient (in these files anonymized to
only gender and age), details of the recording (in particular the recorded time
period), and characteristics of the signals including their amplitude
calibration.

Data from a study of age effects on sleep in healthy subjects

The SC* files (SC = Sleep Cassette) were obtained in a 1987-1991 study of age
effects on sleep in 79 healthy Caucasians aged 25-101, without any sleep-related
medication [2]. Two PSGs of about 20 hours each were
recorded during two subsequent day-night periods at the subjects' homes. File
SC4ssnE0-PSG.edf contains the PSG of subject ss
(00 ≤ ss ≤ 82) for night
n (1 or 2). The first nights of subjects 36 and 52, and the
second night of subject 13, were lost due to a failing cassette or laserdisk.
(The subjects currently included here, numbers 00 through 19, are 10 males and
10 females, and were 25-34 years old at the time of the recordings.) Subjects
continued their normal activities but wore a modified Walkman-like
cassette-tape recorder described in chapter VI.4 (page 92) of Bob’s 1987
thesis [7]. The EOG and EEG signals were each sampled at
100 Hz. The submental-EMG signal was electronically highpass filtered,
rectified and low-pass filtered after which the resulting EMG envelope
expressed in uV rms (root-mean-square) was sampled at 1Hz. Oro-nasal airflow,
rectal body temperature and the event marker were also sampled at 1Hz. Subjects
and recordings are further described in the file headers, in a spreadsheet
(SC-subjects.xls), and
in [2]. The spreadsheet also includes information about
the subjects aged 35-101 whose recordings are not currently available here.

Data from a study of temazepam effects on sleep

The ST* files (ST = Sleep Telemetry) were obtained in a 1994 study of temazepam
effects on sleep in 22 Caucasian males and females without other
medication. Subjects had mild difficulty falling asleep but were otherwise
healthy. The PSGs of about 9 hours were recorded in the hospital during two
nights, one of which was after temazepam intake. Their placebo nights are
available here. File ST7ssnJ0-PSG.edf contains the PSG of
subject ss
(01 ≤ ss ≤ 24; subjects 03 and 23
dropped out of the study) and night n (1 or 2). Subjects wore a
miniature telemetry system with very good signal quality described
in [8]. EOG, EMG and EEG signals were sampled at 100 Hz, and
the event marker at 1 Hz. The physical marker dimension ID+M-E relates to the
fact that pressing the marker (M) button generated two-second deflections from a
baseline value that either identifies the telemetry unit (ID = 1 or 2 if
positive) or marks an error (E) in the telemetry link if negative. Subjects and
recordings are further described in the file headers, in a spreadsheet
(ST-subjects.xls) that also includes information
about the temazepam night recordings not currently available here, and
in [1].

Software for viewing EDF and EDF+ files

Both EDF and EDF+ formats are free and can be viewed using free software
such as:

An easy way to view these recordings using Polyman is to
select File → Open → File(s)... to open
a PSG.edf file and its corresponding .Hypnogram.edf
file; then select
File → Apply Template → Browse... to open
SC-cassette.xml (for an SC PSG)
or ST-telemetry.xml (for an ST
PSG).

Applications using WFDB library
version 10.4.5 (February 2008) or later can read EDF files directly with no
conversion required. Note that the WFDB library does not decode annotations in
EDF+ files, however. The .hyp files in this directory are
PhysioBank-compatible annotation files generated
by rdedfann from
the .Hypnogram.edf (EDF+) files. These .hyp files can be read
directly by LightWAVE, the PhysioBank ATM, WAVE, and other WFDB library-based
applications.